With rapid development of wireless communications, a set of communications system needs to be capable of radiating and receiving multiple bands, so that an antenna matching the communications system needs to radiate and receive the multiple different bands. However, in a lot of communications devices, because of a requirement on integration and miniaturization of the communications devices, there is no sufficient space allocated to antennas of two or more different bands.
To implement integrated design of antennas of different bands in limited space, the antennas of the different bands need to be designed in a same aperture, implementing aperture sharing. A shared-aperture double-frequency or multi-frequency antenna also satisfies requirements of reducing device costs, improving device integration, and promoting intelligent antenna integration. In the prior art, FIG. 1 shows that orthogonal slot antenna arrays are used to implement aperture sharing between slot antenna arrays working in a same frequency band and having different polarization manners. However, this solution does not resolve a problem of sharing an aperture between antenna arrays working in different bands. FIG. 2 shows that multiband microstrip patch antenna arrays and multiband slot antenna arrays are used to implement aperture sharing between antenna arrays working indifferent frequency bands. However, in this solution, only microstrip patch antennas of different bands are processed and designed on a same printed circuit board, and real aperture sharing is not implemented.